It is postulated that one of the most effective strategies to ameliorate health disparities is to reduce tobacco exposure among African-American (AA) children and their parents. Exposure to the deleterious effects of involuntary secondhand smoking remains a major public health hazard; particularly for the most vulnerable in our society ~ children. Population-based surveys indicate that approximately 50% of children manifest exposure to secondhand smoke (SHS); and that AA children exhibit the highest rates of SHS exposure. The high rate of SHS exposure in children is particularly alarming because the life-course of smoking-related diseases such as asthma, hypertension, diabetes and cardiovascular disease have their onset during childhood. We anticipate that children living in the predominately low-income, AA partner community targeted by this MSM CEHD Program are particularly vulnerable to this toxin exposure. However, the causes and pathobiological consequences of SHS exposure in AA children remain poorly defined. This project will provide the first in-depth characterization of the social determinants and effects of SHS exposure on cardiovascular, metabolic and pulmonary health in AA children. These studies will provide new insights that will guide the development of more effective interventions to prevent tobacco exposure in AA families. Our approach utilizes a socio-ecological model of childhood SHS exposure that posits a multi-level interplay between the child's neighborhood characteristics, family context and individual biological factors. Our working hypothesis poses that certain elements in the 'built environment' predispose AA children to increased involuntary tobacco exposure (e.g. high density of tobacco marketing outlets; crowded housing conditions). Secondly, we hypothesize that parents determine childhood SHS exposure by: 1) parent risk behaviors (e.g. parent tobacco smoking), 2) parent health literacy and 3) parent psychosocial factors that influence childhood SHS exposure (perceived stress; social support). The project's specific aims are: Aim 1: Define the neighborhood characteristics, psychosocial factors and parenting behaviors associated with high secondhand smoke exposure in African-American children. Aim 2: Define the relationship between secondhand smoke exposure during childhood and vascular dysfunction, a pre-clinical marker of cardio-metabolic disease. Aim 3: Develop a predictive model to identify vulnerable children at high-risk for SHS exposure.